Tabulating machine



NOV. 4, 1941. N 2,261,551

TABULATING MACHINE Filed Nov. 9, 1957 2 Sheets-Sheet 1 5k 5,2 5.20 1 2: L122 PM 3 54 12 AT'TORNEY Patented Nov. 4, 1941 TABULATING MACHINE Harold Hall Keen, Letchworth, England, assignor to International Business Machines Corporation, New York York, N. Y., a corporation of New Application November 9, 1937, Serial No. 173,563 In Great Britain November 18, 1936 4- Claims. (Cl. 235-51.?)

This invention relates to record card controlled statistical machines of the kind in which cards, arranged in groups, are fed through the machine and in which an automatic group-control mechanism operates to determine from designations recorded in the cards when the last card of the group is passing through the machine and then to interrupt the card-feeding operations of the machine to allow of the total of the group being taken. Normally the automatic group-control mechanism initiates one or more total printing cycles when it interrupts the card feeding operations of the machine.

According to the present invention, there is provided, in a, record card controlled statistical machine, automatic group-control mechanism comprising stop means normally operative at the end of each card feeding cycle-of the machine to interrupt card feeding operations, a card reading device operative to detect the presence of holes in a plurality of hole positions in a card, and a plurality of normally inoperative control devices each associated with a separate one of said hole positions and arranged to be rendered operative by the card reading device when the latter detects a hole in the asso-. ciated position, each arranged to remain operative until just before the stop means operates in the next card feeding cycle and each operative to render the stop means inoperative, to prevent each other control device rendering the stop means inoperative and to maintain any other control device, that is operative in the same cycle, operative until after the stop device has operated in that cycle. With this arrangement each hole position corresponds to a different group and the group to which the card relates is indicated by a hole in the appropriate position. As each card is read, a control device corresponding to the hole will be trol device will prevent the other from render-- ing the stop means inoperative so that the stop means will operate to interrupt card feeding operations of the machine. The card reading derendered operative. If two successive cards belong to the same group, the same control device will be rendered operative in successive cyclesn If two successive cards belong to different groups, two different control devices will be rendered operative in successive cycles and the one that is rendered operative in the first cycle will be maintained operative until after the stop means has operated in the second cycle. Thus both the control means will be operative when the stop means operates. In the first case only one control device will be operative during the second cycle and will render the stop means inoperative so that another card feeding cycle will take place. In thesecond case each convice is arranged in advance of the main card reading device of the machine so that the card feeding operations are interrupted when the first of the two cards considered in the second case has been read by the main reading device which controls the adding and printing functions of the machine. Thus, the card feeding operations will be interrupted when the last card of a group has passed through the machine.

If the first of two successive cards contains a hole and the second contains no hole, a control device will be rendered operative in the first cycle while no control device will be rendered operative in the second cycle. Under these conditions, the control device will become inoperative just before the stop device operates so that the latter can operate to interrupt the card feeding operations. Thus any card which is unpunched in one of the hole positions will not be .treated as belonging to the preceding group of cards. It is desirable that this .card should be treated as constituting a group by itself and should not be included in the succeeding group of cards. This would occur owing to the following card rendering a control device operative so that successive card feeding cycles would oc-' cur. It is, therefore, a feature of this invention to provide a no-hole device arranged to be rendered operative when all the control devices are inoperative during a total printing cycle and to maintain itself operative until the stop means has operated in the next card feeding cycle and operative to prevent any control device rendering the stop means inoperative.

It is desirable to provide means for indicating the particular group to which a printed total relates. It is, therefore, a feature of this invention to provide a device for recording indications of group designations, a plurality of group indicating devices each arranged to be rendered operative by an associated control device, when the latter is operative, each arranged to remain operative until a total printing cycle is performed, and then to become inoperative, each operative to cause the recording device to record an appropriate indication during the total printing cycle and each operative to prevent any other group indicating device being rendered opera- While the present invention is applicable where the-hole positions previously referred to.

are arranged in a column, it is specially intended for use where the hole positions are distributed over several columns since the operation of the mechanism is not dependent on the relative dispositions of the hole positions. Thus, the present invention renders it possible to utilize the so-called x and Y positions which occur at the top of each column on the record card above the to 9 positions. The X and Y positions are only required in the column when that column is to be used to record the month of the year,

pence value or other digits on the duo-decimal notation. The present invention renders it possible to utilize these positions in one or' more columns to record a group designation, thereby increasing the capacity of the card, since it is not necessary to assign a complete column to receive the group designation.

For better understanding of the above and other features of the present invention, a single embodiment in accordance with the present invention, will now be described with reference to the drawings accompanying the specification, in which:

Figs. 1 and is placed one above the other in the order named constitute the wiring diagram of the automatic control mechanism.

Fig. 2 is a timing diagram for the contacts shown in Figs. 1 and 1a.

The arrangement, now to be described, is designed for use in a tabulating machine of the kind known commercially as the "Hollerith total rolling" machine. A machine of this kind is described in U. 8. Patent No. 2,174,699 and, accordingly, only the automatic control circuits of the machine will need be described herein.

The conventional automatic control circuits will first be described to assist in an understanding of the present improvements. In a Hollerith tabulating machine, each card is fed first past upper brushes and then one cycle later past lower brushes. Fields on the cards are assigned to receive group indications and the cards may be divided into major groups, which are sub-divided into intermediate groups, and the intermediate groups may be further subdivided into minor groups, or there may only be two or only one kind of group. Each card contains a field for each kind of group. The automatic control mechanism comprises a number of relays having coils each of which is plug connected between the upper brush and the lower brush that read a column of one of the group designating fields. If two successive cards contain the same hole in one of these columns, the corresponding relay will ,be energized, so that if the two cards belong to the same, say, minor group, all the relays associated with the minor group field will be energized. When energized each relay closes a pair of contacts CMa so that if two successive cards belong to the same minor group, all the minor group contacts CMa will be closed, and similarly for the intermediate and major group contacts.

The machine has a major control circuit ineluding relay coil MA, an intermediate group circuit including coil I and a minor group circuit including coil MI. 80 long as these three circuits are made, the machine will continue card feeding operations. If, however, one or more of these circuits fails, card feeding cycles will be interrupted and the machine will perform a variable number of total printing cycles. The number of cycles performed depends upon the adjustment of the machine and upon which of the three control circuits has failed. During these cycles, minor, intermediate or major totals are printed, depending upon the condition of the control circuits, and the appropriate counters 'in the machine are reset. During the last of these cycles, contacts P6 are closed to complete a circuit through the coil MI, a switch I21 (which is adjusted to the left from the position shown) and contacts L20. The coil MI closes contacts MIa so as to provide a circuit through its contacts, a plug connection 3i between sockets Bill and Bl, the coil I, a switch I22 and cam contacts MI. The coil I closes its contacts Ia to provide a circuit through a plug connection 22 between sockets SI and $1, the coil MA, a switch l2! and contacts L22. The coil MA closes its contacts MAa to provide a connection including a plug connection 22 between sockets S5 and S0. This connection is in parallel to the contacts by which the circuits are set up and serves to maintain the circuits after these contacts have opened.

The contacts L20, L, and L22 open mo- I mentarily in each card feeding cycle and throw the maintenance of the control circuits on to the contacts CMa. In Fig. 1 the contacts CMa are plugged for major, intermediate and minor control from fields each of which contains two columns. By plug connections 24 and it between sockets Si and S2 and $2, the upper pair of contacts, relating to the major group, are connected in parallel with the contacts L22. If the major group does not change, both these pairs of contacts CMa will close and will maintain the major control circuit when the contacts L22 open. Should either of these contacts be open, however, the major control circuit will fail when the contacts L22 open. A plug connection 38 connects both the major and intermediate contacts CMa in parallel with the cam contacts L2i so that the intermeditae control circuit will fail when either a major or an intermediate group change occurs. All the contacts CMa in use are in parallel with the cam contacts L20 so that the minor control circuit will fail on any group change. If it is desired to operate on intermediate and minor group control only, the switch I25 is thrown to the right, while for a minor control only, both the switches I25 and I26 are thrown to the right.

The conventional record card has twelve hole positions in each column and normally only the lower ten are utilized to indicate digits on the decimal notation. The two upper positions are known as the X and Y positions and are utilized when a digit on the duo-decimal notation has to be recorded or in conjunction with the holes in the lower ten positions for indicating the letters of the alphabet. These hole positions may also be used for holes indicating whether amounts are debit or credit. These various uses of the X and Y positions will, however, only account for a proportion of the total X and Y positions on the cards so that by utilizing the X and Y positions not otherwise required, the capacity of the card can be increased. In the arrangement shown in the drawings, it is proposed to utilize the X and Y positions in two columns to indicate the quarters of the year to which a card relates. Thus, a hole in the X position of the first column would indicate the first quarter, a hole in the Y position of the first column would indicate the second quarter, a hole in the x position of the second column the third quarter and a hole in the Y position of the second column the fourth quarter. Cards punched in this manner may be sorted into groups (major, intermediate or minor.

consecutive cards.

as required) in accordance with the quarters. Thus. for example, the cards may be sorted into intermediate groups in accordance with customer numbers on the cards, and to minor groups in accordance with the quarters to which they relate.

. The conventional Hollerith automatic groupcontrol mechanism is dependent upon a comparison of holes in corresponding columns of This condition does not arise with the method of representing quarters indicated above, since the hole representing a quarter may be in either of two columns. The automatic control mechanism is, therefore, modified as will now be described to take care oi? the quarters.

The control circuits are adjusted by throwing the switch I21 to the right, as shown, removing the plug connection 3| and connecting the sockets S9 and SIIl to sockets SII and SI2 by plug connections 31 and 38. This has the effect that the minor control circuit is not dependent on the minor control contacts CMa but is still dependent on the intermediate and major contacts CMa so that it fails in the normal way on intermediate or major group change. The failure of the minor control circuit on the minor group change is brought about in a manner which will be described later. It should be mentioned, however, that the machine can beadjusted for either.intermediate or major control in accordance with the quarters by throwingthe switch I26 or the switch I25 respectively to the right, and plugging the sockets SI I and SI2 to the sockets S1 and S8 or to the sockets S5 and S6 respectively.

The machine is provided with pick-up relays comprising each a pick-up coil IX, 2X, IY or 2Y and a holding coil IXH, 2XH, IYHand 2YH respectively. The coils IX and 2X are in series with contacts T9 and TH) respectively and these contacts close while the X holes in the cards are passing the upper brushes. A socket 39 is connected to the upper brush UBI reading the first column and a socket 40 is connected to the upper brush UB2 reading the second column. Thus, if an X hole is present in the first column, coil IX will be energized while if an X hole is present in the second column, the coil 2X will be energized. The coils IY and 2Y are in series respectively with contacts TH and TI2 which close while the Y hole positions are passing the upper brushes. Sockets AI and 42 are connected respectively to the upper brushes UBI reading the first column and the upper brush UB2 reading the second colunm so that the coil IY will be energized when the Y hole is present in the first column and the coil ZY when the Y hole is present in the second column. As a card passes the upper brushes, one of these four coils will be energized, depending upon the position of the hole in the four hole positions in question. Thus, assuming that the card relates to the first quarter, the coil IX will be energized. The coil IX closes its contacts IXb to energize the holding coil IXH which maintains the contacts IXb closed. The circuit includes cam contacts T2 which are normally closed but open just before the X hole position passes the upper brushes in the next cycle.

Each of these relays forms one part of the control device, the other part of which is constituted by a relay IXT, 2XT, IYT and 2YT. It will be seen that this control device becomes operative when a hole in an associated position is read and remains operative during the first part of the next card feeding cycle. The manner in which it controls the automatic control circuits will next be described.

The coil IXH closes contacts IXa to provide a circuit through contacts PII to the coil IXT. This coil closes contacts IXTb to provide a holding circuit for itself through cam contacts TI3 and the contacts PII. The contacts-TB close early in each cycle and reopen after the X and Y positions have passed the upper brushes. Thus, the coil IXT will be energized when the X hole is read in the first column and will remain energized until after the X and Y holes have been read in the next cycle. If the next card relates to the same group, the coils IX and IXH will be energized by the X hole in the first column and'the contacts IXa will be closed when the contacts TI3 open so that the coil IXT will be maintained energized for another cycle. If the succeeding card belongs to a different group, for example, relates to the second quarter, the coils IY and IYH, for example, will be energized and the contacts IYa will be closed to energize the coil IYT. This coil closes its contacts IYTb. When the contacts TI3 open, the coils IXT and IYT are both energized and the contacts IYa, IYTb and IXTb are closed but the contacts IXa are open. The coil IYT is maintained energized through the contacts IYa and the contacts PII while the coil IXT is maintained energized over a back circuit comprising the contacts IXTb, IYTb, IYa and PI I. It will be seen that two coils IXT and IYT are both energized and indicate that the two successive cards belong to two different groups.

If thesecond card contains no quarter indicating hole, none of the coils IX, 2X, IY and 2Y will be energized at the second cycle and the coil I XT will become deenergized on the opening of the contacts TI3. If the second card contains two holes in the quarter indicating positions two of the coils IX, 2X, IY and 2Y will be energized and two or three coils IXT, ZXT, IYT and ZYT will be energized at the end of a cycle. From the foregoing, it will be seen that, if the two cards belong to the same group, one of the operating coils IXT, ZXT, IYT, 2YT will be energized. On the other hand, if a group change has occurred between the two cards or if the second card is a foreign card, either none of these coils or more than one of these .coils will be energized.

These coils control contacts shown at the top of Fig. 1. These contacts are connected in parallel with contacts TI4 which open at the same time as the contacts TI3. The contacts of the operating coils are arranged to provide four shunt circuits about the contacts TI4 and each of these circuits is associated with one of the operating coils and contains normally open contacts IXTd, ZXTd, I YTd and ZYTd of the associated coil. Each circuit also contains normally closed contacts of the operating coils associated with each other circuit. Each circuit can therefore be made by energizing the associated coil but the concurrent energization of any other coil will provide a second break in the circuit and prevent its being made by the associated coil. Thus, the coil IXT, when energized, closes its contacts IXTd and provides a connection through these contacts, contacts 2XTa, IYTa, ZYTa and Za in parallel with the contacts TM. The contacts TM are connected by the plug wires 31 and v38 in the minor control circuit and they act as and therefore to bring about the interruption of card feeding operations by the machine and the initiation of total printing cycles. With the coil in energized, a shunt is provided about the contacts Til so that the minor control circuit is maintained and the machine will perform another card feeding cycle. If any other coil is energized concurrently with coil ixT, this shunt circuit is not made and the contacts Til will break the minor control circuit. 1 Thus, the coil iYT will open its contacts IYTa to interrupt the shunt connection Just traced. It will also be appreciated that no shunt connection is made if none of the operating coils is energized. Thus, the stop contacts Til will be operative to interrupt the minor control circuit either when none of the operating coils or when more than one of the operating coils is energized, but the energization of one only of these coils renders the contacts Til inoperative.

On a change of group from the first to the second quarter, the coil IYH is energized in the card feeding cycle preceding the total printing cycles and is maintained energized by the contacts TI until the next card feeding cycle since the contacts T2 do not operate in total printing cycles. The contacts Pii open in each total printing cycle to deenergize the coils IXT and iYT. The coil iYT, but not the coil ixT, will be re-energized when the cam contact Pil reclose. The coil IY'I' is thus energized in the cycle following the total printing cycles. The automatic control will then continue to operate as described previously.

A card which contains no quarter designating hole should be treated as a group on itself. It has been explained that such a card will bring about the failure of the minor control circuit when it reaches the upper brushes. If the next card contains a single quarter designating hole, it would energize one of the pick up and one of the operating coils as previously described, and the energization of a single operating coil would serve to prevent the contacts Tll operating to interrupt card feeding operations. The foreign card would thus be treated as one of the cards of the next group. This is prevented by means of a no-hole relay Z. when a foreign card, unpunched in any quarter designating position, passes the upper brushes, all the pick-up relays are deenergized and their contacts ixc, 2X0, iYc and 2Y0 are all closed. During the total printing cycles that follow, cycle relay contacts l! are closed. These contacts form part of a relay, such as the relay MIR described in the specification referred to above, which is energized in a particular total printing cycle, for example, the last, and determines the operation of the machine during that cycle. Cam contacts P8 close in each total printing cycle so that a circuit may be completed through the contacts P8, l3, iXc, 2Xc, life, and 2Y0 and the coil Z. This coil closes contacts Zb to provide a holding circuit through contacts '1! which are shut during all total printing cycles, but open after the contacts Til have opened in the next card feeding cycle. The coil Z also opens its contacts Za so as to break all the shunt connections about the contacts Til. The latter contacts can thus operate to break the minor control circuit so that card feeding operations are interrupted after one cycle and total printing cycles are initiated in respect of the foreign card.

Provision is made for printing against the 2,261,561 1 stop contacts to break the niiiioianmi totalatheminorgroumi t m which;

they relate. For this pose. the coils ixto I? are provided with contacts ixd to 2Y4. When, say, the coil I1! is energized, it closes its contacts ixd to energize a coil in. This coil closes holding contacts lxPe to provide a holding circuit including cycle relay contacts ll which are normally closed. The coil in is thus maintained energized until the total printing cycle in which the contacts ll are opened by their cycle relay, in the same way as contacts l8 above described. Ina similar manner each of the other pick-up coils can energize a group indicating coil 21?, IT? or IYP. It will be noticed that each of the group indicating coils is in series with normany-closed contacts of each other group indicating coil. Thus, when the coil I2? is energized, it opens contacts ixPa, IX?!) and ixPc so that the group indicating coils IXP, iYP and IYP cannot be energized so long as the coil II? is energized. Thus, on a group change from, say, the first to the second quarter, the pick-up coil IY will be energized and will close its contacts iYd. The coil IYP will not, however, be energized, since the contacts ixPb are open. With this arrangement, the group indicating coil, which is first energized in a succession of card feedin cycles, remains energised I until total printing cycles take place and prevents any other group indicating coil being energized.

Assuming that the coil iXP is energized, it closes contacts iXPd to provide a connection between a print magnet P and an emitter El. Print magnet P controls a conventional type bar and arrests the type bar with a particular type on the printing line in accordance with the time of the cycle at which the magnet is energized. The emitter El serves to connect contact segments It in circuit in turn at the times corresponding to the various digits. The contacts iXPd are connected to one of the segments 46 so that a circuit may be completed through them to energize the magnet P at a time appropriate for arresting the type bar in position to print 1. The circuit includes contacts T8, opened during card feeding cycles but closed during total printing cycles, and contacts ll which are closed in the total printing cycle during which the minor totals are printed which may, for instance, belong to the relay which controls the printing of the total from a minor total counter.' Contacts zxpa, iYPd and IYPd of the other group indicating coils are connected in a similar manner to other segments ll so that circuits may be completed through them to control the printing of other symbols. The symbols actually printed may be varied as desired by providing the appropriate type bar. In the example considered, these symbols may be the digits 1, 2, 3 and 4 indicating a quarter to which the total relates.

In some cases the 0 to 9 parts of the two columns containing the quarter indicating holes may form part of a field containing a group number in accordance with which the machine is to be controlled automatically. The two upper and the two lower brushes reading these columns would then be plug connected to the two relay coils controlling two of the contacts CMa as mentioned previously. Circuits should only be completed to these two coils through holes in the 0 to 9 positions in these columns and, to prevent such circuits being made incorrectly through the quarter indicating holes, two circuit makers are provided and are plug connected one in series with each of the relay coils. The circuit makers close only while the to 9 hole positions pass the upper brushes and are open when the quarter indicating hole positions pass these brushes.

It will be appreciated that this form of automatic control may be applied to any desired number of group indicating positions by providing a corresponding number of pick-up, operating and group indicating relays. Thus, if it were desired to effect minor control in accordance with the months of the year, twelve hole positions may be utilized spread over six columns oi. the card and twelve of each class of relay provided instead of four. It will also be appreciated that the arrangement is not restricted to control from the X and Y positions in a column. Thus, for example, a controlin accordance with the months of the year can be obtained by utilizing the X, Y and 0 positions in four columns leaving the l to 9 positions for other purposes.

A few contacts are included in the drawings which bear reference numerals not mentioned in the foregoing specification. These contacts are old and bear no part in the invention but are included with reference numerals corresponding to the reference numerals in British Patent No. 422,135 above referred to in order to assist in identifying the circuit in said patent.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutions and changes in the form' and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is as follows:

1. In a cyclically operating accounting machine having a record analyzing device for analyzing records in succession for perforations in a plurality of index point positions on said records and a control circuit normally completed during the analyzing portion of each cycle by a cyclically operated pair of contacts and opened after the analyzing portion of the cycle by the opening of said contacts; the combination with mechanism for shunting said contacts to prevent saidv circuit from opening including therein a plurality of special control units each associated with a separate one of said index point positions and containing a control relay having normally open contacts and an operating relay companion thereto having normally open and normally closed contacts, means for rendering each said control relay operative under control of the card analyzing device to energize its companion operating relay when said device analyzes a perforation in the associated index point position, whereby a shunt circuit is established through the normally open contacts of the energized companion relay and the normally closed contacts of the companion relays of the other special control units to keep the control circuit completed when the cyclically operating contacts open, said shunt circuit being reestablished each cycle if the relays of the same special control unit and no other become energized.

2. In a cyclically operating accounting machine controlled by record cards having columns with index point positions representing an ordinal series of digit values and special control positions and including a set of analyzing brushes for analyzing said cards in succession for perforations in preselected columns thereof and a control circuit normally'completing during the analyzing portion of each cycle by cyclically 4 operating contacts which open subsequentto the analyzing portion of the cycle to open said circuit; the combination with mechanism for shunting said contacts to prevent said circuit from opening including therein a plurality of special control units each cooperable with a separate one of the predetermined number of special control positions in the selected columns of the cards and each comprising a control relay and a companion operating relay, means for rendering each of said control relays operative under control of the analyzing brushes only upon analysis of a perforation in its related special index point position, means controlled by each control relay upon becoming energized for causing energization of its companion operating relay, and circuit connections established under control of the energized companion relay and the remaining deenergized companion relays of the other special control units for keeping the control circuit completed when the cyclically operating contacts open, whereby said circuit connections are reestablished each cycle as other cards are analyzed if the relays of the some special control unit and no other become energized.

3. In a cyclically operating accounting machine controlled by record cards divided into column with index point positions representing digit values and special control positions and including a card sensing device for sensing said cards in succession for perforations in preselected columns thereof and a control circuit normally completed during the sensing portion of the cycle by cyclically operating contacts which open subsequent to the sensing portion of the cycle to open said circuit; the combination with means for shunting said contacts to prevent the opening of said circuit comprising therein a plurality of special control units each cooperable with a separate one of the special control positions in the selected columns of the cards and each comprising a control relay and a companion operating relay, means rendered eifective under the control of the sensing device only upon sensing of a perforation 'in one of the special positions of a column of a card for energizing a related control relay, means controlled by the latter relay for energizing its companion operating relay, means for maintaining the companion relay energized until after the time for sensing the special index point positions .of the succeeding card by the sensing device during the next cycle, means for restoring the control relay to normal before that time so that it may be energized again if the succeeding card has a perforation in the corresponding special control position, and a shunt circuit established under control of the energized companion relay of one special control unit and the remaining deenergized companion relays of the other units during each cycle to keep the control circuit closed when the cyclically operating contacts open, said shunt circuit being reestablished on succeeding cycles as long as the control relay of the same special control unit and no other is reenergized during the sensing portion of said cycles.

4. In acyclically operating accounting machine controlled by record cards having special index point positions in selected columns thereof and having therein a card sensing device for sensing said cards successively for perforations in said special positions and a control circuit normally completed during the sensing portion of the cycle by cyclically operating contacts which open following the sensing portion of said cycle to open said circuit; the combination with means for shunting said contacts to prevent the opening of said circuit comprising therein a plurality of sets or relays. each set including a control relay and a companion relay and being related to one or the special index point positions of the cards, means controlled by the sensing device upon sensing of a perforation in a special index point position for energizing the related control relay, means whereby the latter control relay upon energization causes operation of its companion relay, cyclically operating means for maintaining the companion relay energized until after the time for sensing the special index point positions of the succeeding card, means for restoring the control relay to normal before that time so that it may be reenergized ii the succeeding card has a perforation in the corresponding special index point position, and a normallyopen shunt circuit established by the operated companion relay of one set it the companion relays of the other sets remain deenergized, said shunt circuit being reestablished each cycle to indicate, as long as the same control relay is reenergized and no other is energized, an agreement between the control perforations of successive cards by maintaining the control circuit closed after the cyclically operated contacts open.

HAROLD HALL KEEN.

W V CERTIFICATE OF CORRECTION.

Patent No. 2,261, 55 November 1 19b1,

HAROLD HALL KEEN.

It is hereby certified that error appears in the printed specification of the abovenumbered patent requiring correction as follows: Page 5, second column, line 2, claim2, for "completing" read -co'mpleted"; and line 51, claim 5, for-"column" r'ead "columnsand that the said Letters Patent should be read with this correction therein that the same may" conform to the record of the case in the Patent Office.

Signed and. sealed this 15th day of January, A. D. 1912.

Henry Van Arsdal'e (Seal) Acting Commissioner of Patents.

W CERTIFICATE OF CORRECTION. 7

Patent No. 2,261,551. November 1;, 191 .1.

HAROLD HALL KEEN.

It is hereby certified that error appears in the printed specification of the abovenumbered patent requiring correction as follows: Page 5, second cclumn, line 2, claim 2, for "completing" resid -completed"; and line 51, claim 5, for "column" r'ead "columns"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office. I

Signed and. sealed this 15th day of January, A. D. 1914.2.

Henry Van Arsdal'e, (Seal) Acting Commissioner of Patents. 

